The present invention relates to a preparation for dyeing keratin fibers, especially of human hair, which contains at least one 4,5-diaminopyrazole derivative and at least one phenylurea derivative. Dyeings of keratin fibers are carried out in that the above-mentioned composition is mixed with an oxidizing agent, applied on the fibers and, after a specified period of action, washed out once again.
The use of phenylureas in dyeing agents is known from the literature. For example, in the German patent 18 10 191, dyeing agents are described, which contain a combination of phenylureas with 1,4-diaminobenzene or 2,5-diaminotoluene sulfate. However, with these agents, the fibers can only be dyed blue, green or violet with a strong blue tint. The German utility model 299 094 27 discloses dyeing agents, which contain, among other things, a combination of certain pyrazoles and N-(3-dimethylamino)-phenylurea. However, these preparations also do not produce a red tint.
There was therefore a continued need for dyeing agents based on phenylurea derivatives, which make brilliant, intensive, pure red tints possible.
Surprisingly, it has now been found that, when a combination of 4,5-diaminopyrazoles of formula (I) and phenylureas of formula (II) are used, an intensive, brilliant, red oxidative dyeing of the hair is possible, intensive pure red tints being obtained even without the addition of further oxidation dye precursors.
The object of the present application therefore is a preparation for dyeing keratin fibers, which is mixed with an oxidizing agent before use and is characterized in that it contains, in a suitable cosmetic carrier, a combination of
at least one 4,5-diaminopyrazole derivative of the general formula (I) or its physically compatible salts 
xe2x80x83in which R is a linear or branched alkyl group with 1 to 6 carbon atoms, a linear or branched monohydroxyalkyl group with 1 to 6 carbon atoms, a linear or branched polyhydroxyalkyl group with 2 to 6 carbon atoms, a linear or branched monoaminoalkyl group with 1 to 6 carbon atoms, a linear or branched polyaminoalkyl group with 2 to 6 carbon atoms, a benzyl group, substituted with a halogen atom, a linear or branched alkyl group with 1 to 6 carbon atoms or a linear or branched alkoxy group with 1 to 6 carbon atoms or an unsubstituted benzyl group, and
at least one phenylurea derivative of the general formula (II) or its physiologically compatible salts, 
xe2x80x83in which R1 represents a hydroxyl group, an amino group, a linear or branched alkylamino group with 1 to 6 carbon atoms, a linear or branched dialkylamino group with 2 to 6 carbon atoms, a linear or branched alkoxy group with 1 to 6 carbon atoms and
R2 represents a hydrogen atom, a halogen atom, a linear or branched alkyl group with 1 to 6 carbon atoms, a linear or branched alkoxy group with 1 to 6 carbon atoms, a linear or branched hydroxyalkyl group with 1 to 6 carbon atoms or a linear or branched polyhydroxyalkyl group with 2 to 6 carbon atoms with the proviso that R2 is not hydrogen when R1 is a dialkylamino group.
Especially preferred derivatives of the general formula (I) are the following compounds or their physiologically compatible salts:
4,5-diamino-1-methyl-1H-pyrazole; 4,5-diamino-1-(4xe2x80x2-methylbenzyl)-pyrazole; 4,5-diamino-1-(2xe2x80x2-hydroxyethyl)-1H-pyrazole; 4,5-diamino-1-benzyl-1H-pyrazole; 4,5-diamino-1-ethyl-1H-pyrazole; 4,5-diamino-1-isopropyl-1H-pyrazole; 4,5-diamino-1-(4xe2x80x2-methoxybenzyl)-1H-pyrazole; 4,5-diamino-1H-pyrazole; 4,5-diamino-1-(3xe2x80x2-methoxybenzyl)-1H-pyrazole and 4,5-diamino-1-(4xe2x80x2-chlorobenzyl)-1H-pyrazole.
Especially preferred derivatives of the general formula (II) are the following compounds or their physiologically compatible salts:
3-ureido-phenol, 2-chloro-5-ureido-phenol, 2-methyl-5-ureido-phenol, 2-methoxy-5-ureido-phenol, 3-amino-4-methyl-phenylurea and 3-amino-4-methoxy-phenylurea.
Although the inventive dye combination leads to excellent red dyeings already without the addition of further dyes, further oxidation dye precursors, such as derivatives of p-phenylenediamine, like 2-(2xe2x80x2,5xe2x80x2-diaminophenyl)ethanol, resorcinol derivates such as resorcinol, 2-methylresorcinol or 4-chlororesorcinol, amino and hydroxy derivatives of 1,3-benzodioxol, naphthalene derivates, such as 1-hydroxynaphthalene, 1,5-dihydroxynaphthalene or 1,7-dihydroxynaphthalene, as well as direct dyes such as 2-amino-4,6-dinitrophenol, 2-ethylamino-4,6-dinitrophenol, 2-[(2xe2x80x2-hydroxyethyl)amino]-4,6-dinitrophenol, 2-amino-6-chloro-4-nitrophenol or 2-chloro-6-ethylamino-4-nitrophenol can be added to the inventive dyeing agent in order to round off the dyeing results.
The compounds of formulas (I) and (II), like the above-described oxidative and direct dyes can be used in the form of the free base as well as in the form of their physiologically compatible salts with organic or inorganic acids, such as hydrochloric acid, phosphoric acid, sulfuric acid, acetic acid, lactic acid or citric acid, especially in the form of the hydrochlorides or sulfates. In the case of phenols, these compounds can also be present as alkali phenolates.
The total concentration of dye precursor in the inventive dyeing preparation is about 0.1 to 20% by weight and preferably 0.2 to 6% by weight. The concentration of the compounds of formulas (I) and (II) as well as of the oxidation dye precursors and direct dyes is about 0.01 to 5% by weight and preferably 0.1 to 4% by weight.
Moreover, the usual cosmetic additives, such as antioxidants like ascorbic acid, thiogylcolic acid or sodium sulfite, perfume oils, complexing agents, wetting agents, emulsifiers, thickeners, grooming materials and other auxiliary materials and additives, suitable for cosmetic agents, may be contained in the inventive dyeing preparation as a component of the cosmetic carrier.
Before, as well as after it is mixed with the oxidizing agent, the inventive dyeing preparation may be prepared, for example, in the form of a solution, especially an aqueous or aqueous-alcoholic solution, a cream or a gel or an emulsion. Its composition represents a mixture of the dyeing components with additives, which are customary for such preparations.
Conventional additives in solutions, creams, emulsions or gels are, for example, solvents, such as water, low molecular weight aliphatic alcohols such as ethanol, n-propanol and isopropanol or glycols, such as glycerin and 1,2-propylene glycol, furthermore wetting agents or emulsifiers from the classes of anionic, cationic, amphoteric or non-ionic surface active substances, such as fatty alcohol sulfates, ethoxylated fatty alcohol sulfates, alkyl sulfonates, alkylbenzenesulfonates, alkyltrimethylammonium salts, alkylbetaines, ethoxylated fatty alcohols, ethoxylated nonylphenols, fatty acids alkanolamides, ethoxylated fatty alcohols, ethoxylated nonylphenols, fatty acid alkanolamides, ethoxylated fatty esters, furthermore thickeners such as higher molecular weight fatty alcohols, starch or cellulose derivatives, furthermore Vaseline, paraffin oil and fatty acids, as well as grooming materials, such as cationic resins, lanolin derivatives, cholesterol, pantothenic acid and betaine. The aforementioned components are used in amounts, customary for such purposes. For example, the wetting agents and emulsifiers are used in concentrations of about 0.5 to 30% by weight (based on the dye carrier composition), the thickeners are used in an amount of about 0.1 to 25% by weight (based on the dye carrier composition) and the grooming agents are used in a concentration of about 0.1 to 5.0% by weight (based on the dye carrier composition).
Directly before use, the inventive hair-dyeing agent is mixed with a liquid oxidizing agent in a suitable ratio. The dyeing agent and the oxidizing agent are mixed together preferably in a ratio by weight of about 5:1 to 1:3, a ratio by weight of 1:1 to 2:2 being particularly preferred.
The pH of the ready-for-use inventive hair dyeing agent, resulting from mixing the preferably alkaline dye carrier composition with the generally acidic oxidizing agent, is affected by the amount of alkali in the dye carrier composition and the amount of acid in the oxidizing agent as well as by the mixing ratio. The pH of the finished hair-dyeing agent is between about 3 and 11 and preferably between 5 and 9.
For adjusting the pH of the dye carrier composition and the oxidizing agent, organic and inorganic acids, such as phosphoric acid, ascorbic acid and lactic acid, or alkalis, such as monoethanolamine, triethanolamine, 2-amino-2-methyl-1-propanol, ammonia, sodium hydroxide solution, potassium hydroxide solution or tris-(hydroxymethyl)-aminomethane can be used depending on the pH that is desired.
When used for the oxidative dyeing of hair, the inventive dyeing agent, described above, is mixed immediately before use with the oxidizing agent and is applied on the hair in an amount, which is sufficient for the hair dyeing treatment and, depending on the fullness of the hair, is in general between about 60 and 200 g of the ready-for-use oxidizing dyeing agent obtained.
As oxidizing agent, mainly hydrogen peroxide or its addition compounds with urea, melamine or sodium bromate in the form of a 1 to 12% and preferably 6% aqueous solution, comes into consideration, hydrogen peroxide being particularly preferred.
The inventive dyeing agent is allowed to act for about 10 to 45 minutes and preferably 25 to 40 minutes (and particularly 30 minutes) on the hair at 15xc2x0 C. to 50xc2x0 C., after which the hair is rinsed with water and dried. Optionally, after this rinsing, the hair is washed with a shampoo and possibly rinsed with a weak organic acid, such as citric acid or tartaric acid. Subsequently, the hair is dried.
The following examples are intended to explain the object of the invention in greater detail without limiting it to these examples.